<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{mso-style-priority:99;
mso-style-link:"Balloon Text Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:8.0pt;
font-family:"Tahoma","sans-serif";}
span.EmailStyle17
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
span.BalloonTextChar
{mso-style-name:"Balloon Text Char";
mso-style-priority:99;
mso-style-link:"Balloon Text";
font-family:"Tahoma","sans-serif";}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Hi Jonas,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I gave a look at this over the week-end, and I believe the attached patch can fix the issue you described. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The patch modifies handleSetCosts so that it only promotes the nodes to the OptimallyReducible or ConservayivelyAllocatable sets once the metadata have been fully updated. And while there, I renamed handleSetCosts to handleUpdateCosts to better reflect what the method does.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Cheers,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>--<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Arnaud<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Jonas Paulsson [mailto:jonas.paulsson@ericsson.com] <br><b>Sent:</b> 06 February 2015 12:22<br><b>To:</b> Lang Hames; Arnaud De Grandmaison<br><b>Cc:</b> llvm-commits@cs.uiuc.edu<br><b>Subject:</b> [PBQP] setEdgeCosts() (was PBQP bugfix)<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-US>Hi Lang,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>The patch seems good to me on my target as well, thank you.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>However, the bug#3 I wrote about earlier is now still merely hidden. The problem is that setEdgeCosts() temporarily disconnects two nodes, moves them to ConservativelyAllocatableNodes because their DeniedOpts have now been decreased by one, and then reconnects them. DeniedOpts gets increased again during reconnection, and the isConservativelyAllocatable() test would then fail, but the nodes have already been moved.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>I resend the test case again along with reverts of patches that hide the bug (for the test case).<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>To investigate:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Revert the two patches that hide the bug (see below), or just apply the attached patches that do the same thing. (To see that there is an error, also apply the patch with an assert that no nodes in coservatively allocatables gets the spill option).<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Then run llc with the attached test case:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>llc pbqp_reduced.ll -mtriple=aarch64-none-linux-gnu -mcpu=cortex-a57 -mattr=+neon -optimize-regalloc -regalloc=pbqp<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>(The assertion triggers, because Node 2 was in conservatively allocatables and yet spilled.)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>The error is made *<b>during applyR2() of node 18</b>*.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Debug dumps (patch for debug dumps not provided, sent earlier):<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>handleDisconnectEdge(9, 2) : DeniedOpts 10 -> 9<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>NId 9(%vreg15, GPR64common) moved to conservatively-allocatables.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>handleDisconnectEdge(2, 9) : DeniedOpts 10 -> 9<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>NId 2(%vreg4, GPR64common) moved to conservatively-allocatables.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Popped NId 2(%vreg4, GPR64common) , all edge costs added:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>2.002748e+01 inf inf inf inf inf inf inf inf inf inf ** selection: 0<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>/Jonas<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:black'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>Attachments:<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>commit 4a44259e80c04c340349ed8f32bcbc8ffdb89b52<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>Author: Jonas Paulsson <<a href="mailto:jonas.paulsson@ericsson.com">jonas.paulsson@ericsson.com</a>><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>Date: Fri Feb 6 10:34:35 2015 +0100<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'> Revert "[PBQP Regalloc] Pre-spill vregs that have no legal physregs."<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'> <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'> This reverts commit d54450ef63998effdb19476c4e4c6c3f0a8c5f50.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>commit 9ada754d86920eba6cbda342e643e235788d139b<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>Author: Jonas Paulsson <<a href="mailto:jonas.paulsson@ericsson.com">jonas.paulsson@ericsson.com</a>><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>Date: Fri Feb 6 10:30:38 2015 +0100<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'> Revert "[PBQP] Fix transposed worst row/column check in handleAdd/RemoveNode in the PBQP"<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'> <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'> This reverts commit 4bde7909b4eb2aba2cd62b79d8cca98d9af6692e.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>commit 45b838cc499a6af384c43fbc2d8c83c17b48f25e<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>Author: Jonas Paulsson <<a href="mailto:jonas.paulsson@ericsson.com">jonas.paulsson@ericsson.com</a>><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>Date: Wed Jan 28 08:30:35 2015 +0100<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'> Assert in PBQP that a node that selects '0' (spilled) was not pushed on node<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'> stack as conservatively allocatable.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='color:black'>Test case: pbqp_reduced.ll<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Lang Hames [<a href="mailto:lhames@gmail.com">mailto:lhames@gmail.com</a>] <br><b>Sent:</b> den 3 februari 2015 07:19<br><b>To:</b> Jonas Paulsson; Arnaud A. de Grandmaison<br><b>Cc:</b> <a href="mailto:llvm-commits@cs.uiuc.edu">llvm-commits@cs.uiuc.edu</a><br><b>Subject:</b> Re: PBQP bugfix<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><div><p class=MsoNormal><span lang=EN-US>Hi Jonas,<o:p></o:p></span></p><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>Apologies for the delay - I've committed my fix for this in r227942.<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>I haven't had a chance to try it out on your ARM test case yet, but hope to soon. Please let me know if it doesn't fix the problem for your out-of-tree target.<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>Cheers,<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>Lang.<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><div><p class=MsoNormal><span lang=EN-US>On Fri, Jan 30, 2015 at 11:10 AM, Lang Hames <<a href="mailto:lhames@gmail.com" target="_blank">lhames@gmail.com</a>> wrote:<o:p></o:p></span></p><div><p class=MsoNormal><span lang=EN-US>Hi Jonas,<o:p></o:p></span></p><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>Thanks very much for tracking this down!<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>I think the best approach to fixing this is to have the PBQP register allocator recognize these nodes early and never represent them in the graph. Any matrix that has only one column must be connected to a node that has only one solution, and this should be allocated up-front to simplify the solver's job.<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>I'll have a fix for this later today.<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>Cheers,<o:p></o:p></span></p></div><div><p class=MsoNormal><span lang=EN-US>Lang.<o:p></o:p></span></p></div></div><div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><div><div><div><p class=MsoNormal><span lang=EN-US>On Thu, Jan 29, 2015 at 9:25 AM, Jonas Paulsson <<a href="mailto:jonas.paulsson@ericsson.com" target="_blank">jonas.paulsson@ericsson.com</a>> wrote:<o:p></o:p></span></p></div></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'><div><div><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=SV>Hi,</span><span lang=EN-US><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=SV> </span><span lang=EN-US><o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>This is a bugfix for the PBQP register allocator. The case for a one-column matrix must be handled in the MatrixMetadata constructor.<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US>See commit message for further explanation,<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US style='color:#888888'> <o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US style='color:#888888'>Jonas Paulsson<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span lang=EN-US style='color:#888888'> <o:p></o:p></span></p></div></div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><span lang=EN-US>_______________________________________________<br>llvm-commits mailing list<br><a href="mailto:llvm-commits@cs.uiuc.edu" target="_blank">llvm-commits@cs.uiuc.edu</a><br><a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits" target="_blank">http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits</a><o:p></o:p></span></p></blockquote></div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></div><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p></div></div></div></body></html>